JP7653779B2 - Polishing cloth - Google Patents
Polishing cloth Download PDFInfo
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- JP7653779B2 JP7653779B2 JP2020168649A JP2020168649A JP7653779B2 JP 7653779 B2 JP7653779 B2 JP 7653779B2 JP 2020168649 A JP2020168649 A JP 2020168649A JP 2020168649 A JP2020168649 A JP 2020168649A JP 7653779 B2 JP7653779 B2 JP 7653779B2
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- 238000005498 polishing Methods 0.000 title claims description 121
- 239000004744 fabric Substances 0.000 title claims description 74
- 239000000463 material Substances 0.000 claims description 42
- 239000004745 nonwoven fabric Substances 0.000 claims description 22
- 238000005259 measurement Methods 0.000 claims description 20
- 239000011347 resin Substances 0.000 claims description 10
- 229920005989 resin Polymers 0.000 claims description 10
- 230000006835 compression Effects 0.000 claims description 5
- 238000007906 compression Methods 0.000 claims description 5
- 230000000052 comparative effect Effects 0.000 description 18
- 238000005470 impregnation Methods 0.000 description 17
- 235000012431 wafers Nutrition 0.000 description 12
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 10
- 239000007788 liquid Substances 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- 238000001878 scanning electron micrograph Methods 0.000 description 9
- 230000007423 decrease Effects 0.000 description 8
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 8
- 239000003960 organic solvent Substances 0.000 description 6
- 238000007665 sagging Methods 0.000 description 6
- 238000011282 treatment Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- CONKBQPVFMXDOV-QHCPKHFHSA-N 6-[(5S)-5-[[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]methyl]-2-oxo-1,3-oxazolidin-3-yl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)C[C@H]1CN(C(O1)=O)C1=CC2=C(NC(O2)=O)C=C1 CONKBQPVFMXDOV-QHCPKHFHSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000003381 stabilizer Substances 0.000 description 2
- 239000011800 void material Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000002591 computed tomography Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Landscapes
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Description
本発明は、研磨布に関する。 The present invention relates to an abrasive cloth.
従来、シリコンウェハなどの被研磨物を研磨するのに、形成材料として、不織布と、該不織布に含浸された樹脂とを備えた研磨布が用いられている（例えば、特許文献１）。 Conventionally, polishing cloths made of nonwoven fabric and resin impregnated into the nonwoven fabric have been used to polish objects such as silicon wafers (see, for example, Patent Document 1).
ここで、研磨布においては、柔軟性が高すぎる場合に端部ダレが生じることが知られている。
樹脂の含浸量を増やして研磨布を硬くすると端部ダレ等の問題を回避できるが、その場合は、研磨布を形成する形成材料の存在比率が高くなる。
被研磨物の研磨時には、形成材料の存在していない部分（空隙）が削り屑の収容スペースとなるため、樹脂の含浸量を増やしすぎると目詰まりし易くなり、その結果、研磨レートが低下しやすくなる。
Here, it is known that if the polishing cloth is too flexible, sagging occurs at the ends.
Problems such as edge sagging can be avoided by increasing the amount of resin impregnation to harden the polishing cloth, but in that case, the presence ratio of the forming material of the polishing cloth increases.
When polishing an object to be polished, the areas where no forming material is present (gaps) become spaces to accommodate shavings, so if the amount of resin impregnation is increased too much, clogging will occur easily, and as a result, the polishing rate will be likely to decrease.
そこで、本発明は、上記問題点に鑑み、適度に樹脂を含有しても研磨レートが低下し難い研磨布を提供することを課題とする。 In view of the above problems, the present invention aims to provide a polishing cloth that does not easily lose its polishing rate even when it contains a moderate amount of resin.
本発明に係る研磨布は、形成材料として、不織布と、該不織布に含浸された樹脂とを備えた研磨布であって、
見掛け密度が０．３０～０．５０ｇ／ｃｍ３であり、
前記形成材料の存在比率の標準偏差が２１．７％以下である。
The polishing cloth according to the present invention is a polishing cloth having a nonwoven fabric and a resin impregnated into the nonwoven fabric as a forming material,
The apparent density is 0.30 to 0.50 g/cm 3 ,
The standard deviation of the abundance ratio of the forming material is 21.7% or less.
また、斯かる研磨布は、前記形成材料の存在比率の標準偏差が２１．７％以下であることにより、研磨布の表面から内部まで空隙の割合が比較的均一になる。そして、斯かる研磨布は、研磨布の表面から内部まで空隙が繋がりやすくなり、その結果、削り屑が多少空隙に詰まっても、研磨レートが低下し難くなる。 In addition, because the standard deviation of the abundance ratio of the forming material in this polishing cloth is 21.7% or less, the proportion of voids is relatively uniform from the surface to the inside of the polishing cloth. And, in this polishing cloth, the voids are easily connected from the surface to the inside of the polishing cloth, so that even if some shavings get stuck in the voids, the polishing rate is unlikely to decrease.
以上より、本発明によれば、適度に樹脂を含有しても研磨レートが低下し難い研磨布を提供し得る。 As described above, the present invention can provide a polishing cloth that is less likely to experience a decrease in polishing rate even when it contains a moderate amount of resin.
以下、添付図面を参照しつつ、本発明の一実施形態について説明する。 One embodiment of the present invention will be described below with reference to the attached drawings.
本実施形態に係る研磨布は、形成材料として、不織布と、該不織布に含浸された樹脂とを備える。
また、本実施形態に係る研磨布では、見掛け密度が０．３０～０．５０ｇ／ｃｍ３であり、前記形成材料の存在比率の標準偏差が２１．７％以下であることが重要である。
また、本実施形態に係る研磨布では、前記形成材料の存在比率の平均値が、好ましくは２２～４５％、より好ましくは３０～４５％、さらに好ましくは３５～４５％である。
The polishing cloth according to this embodiment includes, as its forming materials, a nonwoven fabric and a resin impregnated into the nonwoven fabric.
Moreover, it is important that the polishing cloth according to this embodiment has an apparent density of 0.30 to 0.50 g/cm 3 and that the standard deviation of the abundance ratio of the forming material is 21.7% or less.
In the polishing cloth according to this embodiment, the average abundance ratio of the forming material is preferably 22 to 45%, more preferably 30 to 45%, and even more preferably 35 to 45%.
前記見掛け密度は、０．３０～０．５０ｇ／ｃｍ３であり、好ましくは０．３５～０．５０ｇ／ｃｍ３、より好ましくは０．３５～０．４５ｇ／ｃｍ３である。
なお、見掛け密度は、ＪＩＳ Ｋ７２２２：２００５に基づいて測定できる。
The apparent density is from 0.30 to 0.50 g/cm 3 , preferably from 0.35 to 0.50 g/cm 3 , and more preferably from 0.35 to 0.45 g/cm 3 .
The apparent density can be measured based on JIS K7222:2005.
「形成材料の存在比率の平均値」、及び、「形成材料の存在比率の標準偏差」は、以下のようにして求めることができる。
すなわち、研磨布の表面から裏面まで１００μｍごとの該表面に平行なスライス面に対して、２０００μｍ×２０００μｍの測定面を２つ撮影し（２つの測定面は異なる箇所）、各測定面において、１００μｍ×１００μｍの面を１６８箇所分抽出し、抽出した１００μｍ×１００μｍの各面における形成材料の存在比率を測定する。
そして、測定した形成材料の存在比率の算術平均値を「形成材料の存在比率の平均値」とし、測定した形成材料の存在比率の標準偏差を「形成材料の存在比率の標準偏差」とする。
なお、１００μｍ×１００μｍの各面における形成材料の存在比率とは、１００μｍ×１００μｍの各面において、各面の面積全体を１００％としたときにおける、形成材料が存在する部分の面積の割合を意味する。
例えば、表面から裏面まで間で１００μｍ～１２００μｍまでのスライス面に対して観察する場合には、１６８×１２×２個分の１００μｍ×１００μｍの面の形成材料の存在比率を測定することになる。
The "average value of the abundance ratio of the forming material" and the "standard deviation of the abundance ratio of the forming material" can be determined as follows.
That is, two measurement surfaces of 2000 μm x 2000 μm are photographed (the two measurement surfaces are different locations) for a slice surface parallel to the surface every 100 μm from the front to the back of the abrasive cloth, and 168 surfaces of 100 μm x 100 μm are extracted from each measurement surface, and the abundance ratio of the forming material in each of the extracted 100 μm x 100 μm surfaces is measured.
The arithmetic mean value of the measured abundance ratios of the forming materials is defined as the "average abundance ratio of the forming materials," and the standard deviation of the measured abundance ratios of the forming materials is defined as the "standard deviation of the abundance ratio of the forming materials."
The abundance ratio of the forming material in each 100 μm × 100 μm surface means the ratio of the area of the portion where the forming material is present when the entire area of each 100 μm × 100 μm surface is taken as 100%.
For example, when observing a sliced surface having a thickness of 100 μm to 1200 μm from the front surface to the back surface, the abundance ratio of the material forming the surface of 168×12×2 pieces of 100 μm×100 μm is measured.
前記測定では、ＣＴ－ｓｃａｎにより研磨布を撮影する。
具体的には、研磨布の表面から裏面まで１００μｍごとの該表面に平行なスライス面に対して、２０００μｍ×２０００μｍの測定面を２つ撮影し（２つの測定面は異なる箇所）、各測定面において、１００μｍ×１００μｍの面を１６８箇所分抽出し、１００μｍ×１００μｍの各面の画像において、空隙と空隙以外の部分（形成材料が存在する部分）とに分類する二値化処理をすることにより、観測面における前記形成材料の存在比率（面積比率）を測定する。
ＣＴ装置としては、ヤマト科学株式会社製の三次元計測Ｘ線ＣＴ装置（ＴＤＭ１０００Ｈ－１）を用いることができる。
また、ＣＴ画像処理ソフトとしては、日本ビジュアルサイエンスボリュームグラフィックス株式会社製の画像処理ソフトＶＧＳｔｕｄｉｏ Ｍａｘ ２．１を用いることができる。
さらに、形成材料の存在比率（面積比率）を算出する画像解析ソフトとしては、ＩｍａｇｅＪ（Ｒａｓｂａｎｄ，Ｗ．Ｓ．，Ｕ．Ｓ．Ｎａｔｉｏｎａｌ Ｉｎｓｔｉｔｕｔｅｓ ｏｆ Ｈｅａｌｔｈ，Ｂｅｔｈｅｓｄａ，Ｍａｒｙｌａｎｄ，ＵＳＡ）を用いることができる。
In the measurement, the polishing cloth is photographed by CT-scan.
Specifically, two 2000 μm x 2000 μm measurement surfaces are photographed (the two measurement surfaces are different locations) for a slice surface parallel to the surface of the abrasive cloth every 100 μm from the front to the back, and 168 100 μm x 100 μm surfaces are extracted from each measurement surface. The images of each 100 μm x 100 μm surface are then subjected to a binarization process to classify them into voids and non-void areas (areas where the forming material is present), thereby measuring the presence ratio (area ratio) of the forming material on the observation surface.
As the CT device, a three-dimensional measuring X-ray CT device (TDM1000H-1) manufactured by Yamato Scientific Co., Ltd. can be used.
As the CT image processing software, image processing software VG Studio Max 2.1 manufactured by Japan Visual Science Volume Graphics Co., Ltd. can be used.
Furthermore, as image analysis software for calculating the abundance ratio (area ratio) of the forming materials, ImageJ (Rasband, W.S., U.S. National Institutes of Health, Bethesda, Maryland, USA) can be used.
例えば、以下のような条件で、前記形成材料の存在比率（面積比率）を測定する。 For example, the presence ratio (area ratio) of the forming material is measured under the following conditions:
前記測定においては、以下の視野の大きさで研磨布の測定面を連続測定する。
視野の大きさ（縦×横×高さ） ： ２，０００μｍ × ２，０００μｍ × 厚み方向全域
また、前記測定の条件は、以下の通りである。
１回転あたりのビュー数 ： １５００
フレーム数／ビュー ： １０
Ｘ線管電圧〔ＫＶ〕 ： ２８．０００
拡大軸位置〔ｍｍ〕 ： ７．４１６
再構成の画素サイズＸ〔ｍｍ〕 ： ０．００３８８０
再構成の画素サイズＹ〔ｍｍ〕 ： ０．００３８８０
再構成の画素サイズＺ〔ｍｍ〕 ： ０．００３８８０
In the above measurement, the measurement surface of the polishing cloth is continuously measured with the following field of view size.
Size of field of view (length x width x height): 2,000 μm x 2,000 μm x entire area in thickness direction. The measurement conditions are as follows.
Views per rotation: 1500
Frames/view: 10
X-ray tube voltage [KV]: 28.000
Magnification axis position [mm]: 7.416
Reconstruction pixel size X [mm]: 0.003880
Reconstruction pixel size Y [mm]: 0.003880
Reconstruction pixel size Z [mm]: 0.003880
各測定面において、空隙と空隙以外の部分（形成材料が存在する部分）とに分類する二値化処理は、以下の通りである。
二値化処理では、ＶＧＳｔｕｄｉｏ Ｍａｘで、空隙と空隙以外の部分（形成材料が存在する部分）とに分類するために、測定面の画像に関して、コントラストの調整を行う。
コントラストの調整は、Ｒａｍｐモードで行う。
コントラストの調整では、空隙と空隙以外の部分（形成材料が存在する部分）との違いが明確になるようにする。
ＶＧＳｔｕｄｉｏ Ｍａｘでは、コントラストの調整が“不透明度調整”と表記されている。
具体的には、ＶＧＳｔｕｄｉｏ Ｍａｘの不透明度調整の画面において、グレイバリューの下限値をピークに設定し、次にグレイバリューの上限値を「該ピークのピーク値＋１００±５」の範囲に設定する。なお、材料によって光の透過率が異なるので、コントラストの調整範囲は必ずしもこの限りではない。
The binarization process for classifying each measurement surface into voids and non-void portions (portions where forming material exists) is as follows.
In the binarization process, in VG Studio Max, the contrast of the image of the measurement surface is adjusted in order to classify the area into voids and areas other than the voids (areas where the forming material exists).
Contrast adjustment is performed in Ramp mode.
The contrast is adjusted so that the difference between the voids and the areas other than the voids (areas where the forming material exists) becomes clear.
In VG Studio Max, contrast adjustment is listed as "opacity adjustment."
Specifically, in the opacity adjustment screen of VG Studio Max, the lower limit of the gray value is set to the peak, and then the upper limit of the gray value is set to the range of "peak value of the peak + 100 ± 5". Note that since the light transmittance differs depending on the material, the contrast adjustment range is not necessarily limited to this.
前記コントラストの調整をした２Ｄ画像に対し、測定面の画像を取得する。 An image of the measurement surface is obtained from the 2D image with the contrast adjusted.
次に、前記取得した測定面の画像について、ＩｍａｇｅＪで形成材料の存在比率を測定する。
ここで、ＩｍａｇｅＪにおける測定範囲は１２００μｍ×１４００μｍである。画像データの左上を（ｘ，ｙ）＝（０ｐｉｘ，０ｐｉｘ）位置とし、（１３２，２２）位置から横３１２ｐｉｘ（＝１２０１．２μｍ）、縦３６４ｐｉｘ（＝１４０１．４μｍ）を測定範囲とする。その後、画像タイプをＲＧＢ ｃｏｌｏｒから８ｂｉｔへ変換し、画像を二値化する。この二値化条件において、階調範囲が“１２９”～“２５５”の範囲が、形成材料が存在する部分にあたる。この画像データを横１２ｐｉｘ×縦１４ｐｉｘへ画像サイズを縮小させる。この縮小画像の１ｐｉｘ×１ｐｉｘが１００μｍ×１００μｍの面となる。この操作を表面から裏面まで厚み方向について１００μｍごとに行う。
なお、ＩｍａｇｅＪにおける二値化処理では、階調範囲が“１２９”～“２５５”の範囲となる部分を、空隙以外の部分（形成材料が存在する部分）とする。
Next, the abundance ratio of the forming material is measured for the acquired image of the measurement surface using ImageJ.
Here, the measurement range in ImageJ is 1200 μm x 1400 μm. The upper left corner of the image data is set to the (x, y) = (0 pix, 0 pix) position, and the measurement range is 312 pix (= 1201.2 μm) horizontally and 364 pix (= 1401.4 μm) vertically from the (132, 22) position. After that, the image type is converted from RGB color to 8 bit, and the image is binarized. Under this binarization condition, the range of gradation from "129" to "255" corresponds to the part where the forming material exists. The image size of this image data is reduced to 12 pix horizontally x 14 pix vertically. 1 pix x 1 pix of this reduced image becomes a surface of 100 μm x 100 μm. This operation is performed every 100 μm in the thickness direction from the front surface to the back surface.
In the binarization process in ImageJ, the areas with a gradation range of "129" to "255" are regarded as areas other than voids (areas where forming material exists).
本実施形態に係る研磨布の圧縮率は、好ましくは５％以下、より好ましくは３．５％以下である。
なお、圧縮率は、以下の方法で求めることができる。
すなわち、ＪＩＳ Ｌ１０９６：２０１０に記載の圧縮弾性試験機（圧力子の面積：５０ｍｍ２）を用い、圧力子で研磨布に３００ｇｆ／ｃｍ２の圧力で厚み方向に加圧して６０秒間保持した後の研磨布の厚みＴ１を測定し、次に、圧力子で研磨布に１８００ｇｆ／ｃｍ２の圧力で厚み方向に加圧して６０秒間保持した後の研磨布の厚みＴ２を測定し、下記式により圧縮率を求めることができる。
圧縮率 ＝ （Ｔ１－Ｔ２）×１００／Ｔ１
The compressibility of the polishing cloth according to this embodiment is preferably 5% or less, and more preferably 3.5% or less.
The compression ratio can be calculated by the following method.
That is, using a compression elasticity tester (indenter area: 50 mm2 ) described in JIS L1096:2010, the abrasive cloth is pressed in the thickness direction with the indenter at a pressure of 300 gf/ cm2 and held for 60 seconds, after which the thickness T1 of the abrasive cloth is measured, and then the abrasive cloth is pressed in the thickness direction with the indenter at a pressure of 1800 gf/ cm2 and held for 60 seconds, after which the thickness T2 of the abrasive cloth is measured, and the compression ratio can be calculated using the following formula.
Compression ratio = (T1-T2) x 100/T1
本実施形態に係る研磨布の硬度（Ａｓｋｅｒ－Ｃ）は、好ましくは８０以上、より好ましくは８５～９５である。
本実施形態に係る研磨布は、硬度が８０以上であることにより、被研磨物（例えば、ウェハ等）の端部ダレが生じ難くなるという利点を有する。また、本実施形態に係る研磨布は、硬度が９５以下であることにより、被研磨物に、欠陥（例えば、傷など）が生じ難くなるという利点を有する。
なお、硬度は、ＳＲＩＳ０１０１（日本ゴム協会標準規格）の規定に従って測定した値を意味する。また、Ａｓｋｅｒ－Ｃ硬度は、前記一方の表面で測定する。言い換えれば、硬度は、研磨面で測定する。
The hardness (Asker-C) of the polishing cloth according to this embodiment is preferably 80 or more, and more preferably 85 to 95.
The polishing cloth according to the present embodiment has an advantage that the edge sagging of the workpiece (e.g., wafer, etc.) is unlikely to occur due to the hardness of 80 or more. In addition, the polishing cloth according to the present embodiment has an advantage that the workpiece is unlikely to have defects (e.g., scratches, etc.) due to the hardness of 95 or less.
The hardness is a value measured according to SRIS0101 (the standard of the Society of Rubber Industry, Japan). The Asker-C hardness is measured on the one surface. In other words, the hardness is measured on the polished surface.
本実施形態に係る研磨布の厚みは、好ましくは０．８～２．０ｍｍ、より好ましくは１．０～１．５ｍｍである。
本実施形態に係る研磨布は、厚みが０．８ｍｍ以上であることにより、研磨機の定盤の状態による研磨性能への悪影響を緩和しやすくなるという利点を有する。また、これにより、例えば、被研磨物を安定的に平坦にしやすくなるという利点もある。
また、本実施形態に係る研磨布は、厚みが２．０ｍｍ以下であることにより、研磨時の研磨布の変形量を少なくでき、その結果、被研磨物の端部ダレが生じ難くなるという利点を有する。
The thickness of the polishing cloth according to this embodiment is preferably 0.8 to 2.0 mm, and more preferably 1.0 to 1.5 mm.
The polishing cloth according to the present embodiment has an advantage that the thickness of the polishing cloth is 0.8 mm or more, and therefore the adverse effect on the polishing performance caused by the state of the polishing machine surface plate can be easily alleviated. This also has the advantage that, for example, the workpiece can be easily and stably flattened.
Furthermore, since the polishing cloth according to this embodiment has a thickness of 2.0 mm or less, the amount of deformation of the polishing cloth during polishing can be reduced, which has the advantage that sagging of the edges of the workpiece to be polished is less likely to occur.
前記不織布を構成する繊維としては、ポリエステル繊維、ナイロン繊維などが挙げられる。
前記不織布の目付けは、好ましくは２００～６００ｇ／ｍ２である。
本実施形態に係る研磨布は、不織布の目付けが２００ｇ／ｍ２以上であることにより、硬度が高くなりやすくなり、その結果、被研磨物の端部ダレが生じ難くなるという利点を有する。また、本実施形態に係る研磨布は、不織布の目付けが２００～６００ｇ／ｍ２であることにより、研磨面に空隙部分を適度な割合で有しやすくなる。その結果、本実施形態に係る研磨布は、斯かる構成により、研磨屑等による空隙の目詰まりによって研磨性能が変動するのを、抑制しやすくなるといった利点を有する。
Examples of the fibers constituting the nonwoven fabric include polyester fibers and nylon fibers.
The nonwoven fabric preferably has a basis weight of 200 to 600 g/ m2 .
The polishing cloth according to this embodiment has an advantage that the hardness is easily increased by the nonwoven fabric having a basis weight of 200 g/ m2 or more, and as a result, the end sagging of the polished object is less likely to occur. In addition, the polishing cloth according to this embodiment has a basis weight of 200 to 600 g/ m2 , and therefore the polishing surface is more likely to have a moderate proportion of voids. As a result, the polishing cloth according to this embodiment has an advantage that such a configuration makes it easier to suppress fluctuations in polishing performance due to clogging of voids by polishing debris, etc.
前記樹脂としては、ウレタン樹脂等が挙げられる。 Examples of the resin include urethane resin.
本実施形態に係る研磨布で研磨する被研磨物としては、シリコンウェハなどが挙げられる。 Examples of objects to be polished with the polishing cloth of this embodiment include silicon wafers.
本実施形態に係る研磨布は、上記の如く構成されているが、次に、本実施形態に係る研磨布の製造方法について説明する。 The polishing cloth according to this embodiment is configured as described above. Next, we will explain the manufacturing method of the polishing cloth according to this embodiment.
以下、本実施形態に係る研磨布の製造方法について、ウレタン樹脂を不織布に湿式含浸し、更に、ウレタン樹脂を不織布に乾式含浸するといった二段階含浸処理を行う方法を例に挙げて説明する。 The manufacturing method of the polishing cloth according to this embodiment will be described below using as an example a method of performing a two-stage impregnation process in which the urethane resin is wet-impregnated into the nonwoven fabric, and then the urethane resin is dry-impregnated into the nonwoven fabric.
湿式含浸では、ウレタン樹脂を水溶性有機溶媒に溶解させて第１の含浸液を得る。
水溶性有機溶媒としては、ジメチルホルムアミド、ジメチルスルホキシド、テトラヒドロフラン、ジメチルアセトアミドなどが挙げられる。
なお、第１の含浸液は、充填剤を含有してもよい。該充填剤としてはカーボンブラック等が挙げられる。また、第１の含浸液は、分散安定剤を含有してもよい。該分散安定剤としては、界面活性剤等が挙げられる。
次に、第１の含浸液に不織布を漬け、第１の含浸液に漬けた不織布を水に漬ける。これにより、不織布に付着した第１の含浸液のうち水溶性有機溶媒が水に置換されて、ウレタン樹脂が凝固し、不織布の表面でウレタン樹脂が付着する。
In the wet impregnation, a urethane resin is dissolved in a water-soluble organic solvent to obtain a first impregnation liquid.
Examples of the water-soluble organic solvent include dimethylformamide, dimethylsulfoxide, tetrahydrofuran, and dimethylacetamide.
The first impregnation liquid may contain a filler. Examples of the filler include carbon black. The first impregnation liquid may contain a dispersion stabilizer. Examples of the dispersion stabilizer include a surfactant.
Next, the nonwoven fabric is immersed in the first impregnation liquid, and the nonwoven fabric that has been immersed in the first impregnation liquid is immersed in water, whereby the water-soluble organic solvent in the first impregnation liquid attached to the nonwoven fabric is replaced with water, the urethane resin coagulates, and the urethane resin adheres to the surface of the nonwoven fabric.
乾式含浸では、末端基としてイソシアネート基を有するプレポリマーと、活性水素を有する有機化合物たる硬化剤と、有機溶媒とを混合して、第２の含浸液を得る。
前記有機溶媒としては、メチルエチルケトン、アセトン、アルコール、酢酸エチルなどが挙げられる。
そして、湿式含浸した不織布を第２の含浸液に漬け、第２の含浸液に漬けた不織布を乾燥炉で加熱する。これにより、有機溶媒が蒸発され、プレポリマーと硬化剤とが硬化反応してウレタン樹脂が形成され、その結果、不織布の表面にさらなるウレタン樹脂が付着する。
In the dry impregnation, a prepolymer having an isocyanate group as a terminal group, a curing agent which is an organic compound having active hydrogen, and an organic solvent are mixed to obtain a second impregnation liquid.
Examples of the organic solvent include methyl ethyl ketone, acetone, alcohol, and ethyl acetate.
The wet-impregnated nonwoven fabric is then immersed in a second impregnation liquid, and the nonwoven fabric immersed in the second impregnation liquid is heated in a drying oven, whereby the organic solvent is evaporated and the prepolymer and the curing agent undergo a curing reaction to form a urethane resin, resulting in further adhesion of the urethane resin to the surface of the nonwoven fabric.
本実施形態に係る研磨布は、上記のように構成されているので、以下の利点を有するものである。 The polishing cloth according to this embodiment is configured as described above and has the following advantages:
即ち、本実施形態に係る研磨布は、形成材料として、不織布と、該不織布に含浸された樹脂とを備えた研磨布である。また、本実施形態に係る研磨布は、見掛け密度が０．３０～０．５０ｇ／ｃｍ３であり、前記形成材料の存在比率の標準偏差が２１．７％以下である。 That is, the polishing cloth according to this embodiment is a polishing cloth having a nonwoven fabric and a resin impregnated in the nonwoven fabric as a forming material. The polishing cloth according to this embodiment has an apparent density of 0.30 to 0.50 g/ cm3 , and the standard deviation of the abundance ratio of the forming material is 21.7% or less.
斯かる研磨布は、前記見掛け密度が０．５０ｇ／ｃｍ３以下であることにより、空隙を多く有しやすくなるので、削り屑が多少空隙に詰まっても、研磨レートが低下し難くなる。
また、本実施形態に係る研磨布は、前記形成材料の存在比率の標準偏差が２１．７％以下であることにより、研磨布の表面から内部まで空隙の割合が比較的均一になる。そして、斯かる研磨布は、研磨布の表面から内部まで空隙が繋がりやすくなり、その結果、削り屑が多少空隙に詰まっても、研磨レートが低下し難くなる。
さらに、斯かる研磨布は、前記見掛け密度が０．３０ｇ／ｃｍ３以上であることにより、材料が存在する箇所を多くでき、硬度が高いものとなり、その結果、端部ダレが生じ難くなる。
Since such an abrasive cloth has an apparent density of 0.50 g/cm 3 or less, it is likely to have many voids, so that even if some shavings become clogged in the voids, the polishing rate is unlikely to decrease.
In addition, the polishing cloth according to this embodiment has a standard deviation of the abundance ratio of the forming material of 21.7% or less, so that the ratio of voids is relatively uniform from the surface to the inside of the polishing cloth. And, in this polishing cloth, the voids are easily connected from the surface to the inside of the polishing cloth, so that even if some shavings are clogged in the voids, the polishing rate is unlikely to decrease.
Furthermore, since the polishing cloth has an apparent density of 0.30 g/cm 3 or more, the number of locations where the material is present can be increased, resulting in high hardness, and as a result, sagging at the ends is less likely to occur.
なお、本発明に係る研磨布は、上記実施形態に限定されるものではない。また、本発明に係る研磨布は、上記した作用効果によっても限定されるものでもない。本発明に係る研磨布は、本発明の要旨を逸脱しない範囲で種々の変更が可能である。 The polishing cloth according to the present invention is not limited to the above embodiment. The polishing cloth according to the present invention is also not limited by the above-mentioned effects. The polishing cloth according to the present invention can be modified in various ways without departing from the gist of the present invention.
例えば、本実施形態では、二段階含浸処理を行う方法で研磨布を得ているが、湿式含浸或いは乾式含浸のみで研磨布を得てもよい。 For example, in this embodiment, the polishing cloth is obtained by a two-stage impregnation process, but the polishing cloth may be obtained by only wet impregnation or dry impregnation.
次に、実施例および比較例を挙げて本発明についてさらに具体的に説明する。 Next, the present invention will be explained in more detail with reference to examples and comparative examples.
表１、２に物性を示す実施例の研磨布を作製した。表１、２に物性を示す研磨布（市販品）を用意した。
なお、硬度、圧縮率、見掛け密度、形成材料の存在比率の平均値、形成材料の存在比率の標準偏差は上述した方法で測定した。
また、通気抵抗値（以下「ＡＰＲ」ともいう。）は、図１に示す装置を用い、空気を研磨布の厚み方向に通過させた際（空気の流量：３０Ｌ／ｍｉｎ、空気の圧力：１００Ｐａ）の損失した圧力を意味する。
Polishing cloths of the examples were produced, the physical properties of which are shown in Tables 1 and 2. Polishing cloths (commercially available products) whose physical properties are shown in Tables 1 and 2 were prepared.
The hardness, compressibility, apparent density, average value of the abundance ratio of the forming material, and standard deviation of the abundance ratio of the forming material were measured by the methods described above.
The air flow resistance value (hereinafter also referred to as "APR") means the pressure loss when air is passed through the polishing cloth in the thickness direction using the device shown in Figure 1 (air flow rate: 30 L/min, air pressure: 100 Pa).
図２には、実施例１－１、２－１及び比較例１－１の研磨布の各断面における形成材料の存在比率の算術平均値を示す。
また、図３には、実施例５－１、６－１及び比較例２－１の研磨布の各断面における形成材料の存在比率の算術平均値を示す。
FIG. 2 shows the arithmetic mean values of the abundance ratios of the forming materials in each cross section of the polishing pads of Examples 1-1, 2-1 and Comparative Example 1-1.
FIG. 3 also shows the arithmetic mean values of the abundance ratios of the forming materials in each cross section of the polishing pads of Examples 5-1, 6-1 and Comparative Example 2-1.
密度が０．４ｇ／ｃｍ３を超える研磨パッドと、密度が０．４ｇ／ｃｍ３以下の研磨パッドとは、下記のように条件を変えて評価した。
１）密度０．４ｇ／ｃｍ３を超える研磨パッド：比較例１－１～１－３，実施例１－１～１－３，実施例２－１～２－３，実施例３，実施例４
研磨パッドを用いてウェハを研磨した時の研磨レートを測定した。
測定は、研磨布を装置にセットした後で且つ研磨前にドレス処理を下記の条件のもと流水下で５分間行った後に実施した。
ドレッサー：Ｋｉｎｉｋ製ペレットタイプ ドレッサー♯１５０（直径２０ｍｍペレットをプレート下１２個配置)
荷重：１８．７ｋｇ
回転数：Ｈｅａｄ／Ｐｌａｔｅｎ＝１００／１１５ｒｐｍ
２）密度０．４ｇ／ｃｍ３以下の研磨パッド：比較例２－１～２－３，実施例５－１～５－３，実施例６－１～６－３
ドレス処理を行わずに研磨レートを測定したこと以外は密度０．４ｇ／ｃｍ３以上の研磨パッドと同様に評価した。
The polishing pads having a density of more than 0.4 g/cm 3 and the polishing pads having a density of 0.4 g/cm 3 or less were evaluated under different conditions as described below.
1) Polishing pads with a density exceeding 0.4 g/ cm3 : Comparative Examples 1-1 to 1-3, Examples 1-1 to 1-3, Examples 2-1 to 2-3, Example 3, Example 4
The polishing rate was measured when a wafer was polished using the polishing pad.
The measurement was carried out after the polishing cloth was set in the apparatus and after dressing treatment was carried out for 5 minutes under running water under the following conditions before polishing.
Dresser: Kinik pellet type dresser #150 (12 pellets with a diameter of 20 mm placed under the plate)
Load capacity: 18.7kg
Rotation speed: Head/Platen = 100/115 rpm
2) Polishing pads with a density of 0.4 g/cm3 or less: Comparative Examples 2-1 to 2-3, Examples 5-1 to 5-3, Examples 6-1 to 6-3
Except for the fact that the removal rate was measured without carrying out the dressing treatment, the evaluation was carried out in the same manner as for polishing pads having a density of 0.4 g/cm 3 or more.
研磨レートの測定の際の研磨条件を以下に示す。
研磨ごとに（ランごとに）ウェハの重量を測定し、研磨前のウェハの重量と研磨後のウェハの重量との差から研磨レート（Ｒｅｍｏｖａｌ ｒａｔｅ（ＲＲ））を求めた。結果の一部を図４、図５に示す。
なお、「研磨レート低下率」は、下記式で求めた。結果を表１、２、図６、７に示す。
研磨レート低下率（％） ＝ （研磨レートの最大値－研磨レートの最小値）／研磨レートの最大値 × １００（％）
また、ラン間では、目詰まりを解消させるような処理（例えば、ドレス、ブラシ、ＨＰＭＪ（超高圧マイクロジェット洗浄）による処理）などは行わなかった。
研磨時間：１ｒｕｎのみ６０分間、２ｒｕｎからは４０分間
ｒｕｎ：７回（見掛け密度が０．４０ｇ／ｃｍ３以下の研磨パッドについては、６回）
研磨機：Ｓｔｒａｓｂａｕｇｈ ６ＣＡ
ウェハ：８”（Ｐ－）
研磨液：いずれの研磨液もＤＩＷ（純水）への添加率７．１４％
・密度０．４ｇ／ｃｍ３超の研磨布：固形分（１１５℃）３６．６％、平均粒子径１０８ｎｍ、ｐＨ＝１１．３の溶液
・密度０．４ｇ／ｃｍ３以下の研磨布：ＮＰ６５０３（ニッタ・ハース株式会社製）
研磨液の流量：３００ｍＬ／ｍｉｎ
研磨時間：４０ｍｉｎ／ｒｕｎ
また、実施例１－１、比較例１－１、実施例５－１、比較例２－１の研磨布の表面及び断面のＳＥＭ画像を図８～１５に示す。
The polishing conditions for measuring the polishing rate are shown below.
The weight of the wafer was measured for each polishing (for each run), and the removal rate (RR) was calculated from the difference between the weight of the wafer before polishing and the weight of the wafer after polishing. Some of the results are shown in Figures 4 and 5.
The "polishing rate decrease rate" was calculated by the following formula: The results are shown in Tables 1 and 2 and in FIGS.
Polishing rate decrease rate (%)=(maximum polishing rate-minimum polishing rate)/maximum polishing rate×100 (%)
Furthermore, no treatments to remove clogging (such as dressing, brushing, or HPMJ (ultra-high pressure microjet cleaning) treatments) were performed between runs.
Polishing time: 60 minutes for run 1 only, 40 minutes from run 2 onwards Run: 7 times (6 times for polishing pads with an apparent density of 0.40 g/cm3 or less )
Polishing machine: Strasbaugh 6CA
Wafer: 8" (P-)
Polishing solution: The addition rate of each polishing solution to DIW (pure water) was 7.14%.
Polishing cloth with a density of more than 0.4 g/cm3: solution with a solid content (115°C) of 36.6%, an average particle size of 108 nm, and a pH of 11.3 Polishing cloth with a density of 0.4 g/cm3 or less : NP6503 (manufactured by Nitta Haas Co., Ltd.)
Flow rate of polishing liquid: 300 mL/min
Polishing time: 40min/run
8 to 15 show SEM images of the surfaces and cross sections of the polishing pads of Example 1-1, Comparative Example 1-1, Example 5-1, and Comparative Example 2-1.
図６、７及び表１、２に示すように、実施例の研磨布では、比較例に比べて研磨レートの低下率が小さかった。 As shown in Figures 6 and 7 and Tables 1 and 2, the polishing rate decline was smaller with the polishing cloth of the embodiment than with the comparative example.
Claims (4)
見掛け密度が０．３０～０．５０ｇ／ｃｍ３であり、
前記研磨布の表面から裏面まで１００μｍごとの該表面に平行なスライス面に対して、２０００μｍ×２０００μｍの測定面を２つ撮影し（２つの測定面は異なる箇所）、各測定面において、１００μｍ×１００μｍの面を１６８箇所分抽出し、抽出した１００μｍ×１００μｍの各面において測定される前記形成材料の存在比率の標準偏差が２１．７％以下である、研磨布。 A polishing cloth comprising a nonwoven fabric and a resin impregnated in the nonwoven fabric as a forming material,
The apparent density is 0.30 to 0.50 g/cm 3 ,
A polishing cloth in which two measurement surfaces of 2000 μm x 2000 μm are photographed (the two measurement surfaces are different locations) for a slice surface parallel to the surface every 100 μm from the front to the back of the polishing cloth, and 168 surfaces of 100 μm x 100 μm are extracted from each measurement surface, and the standard deviation of the abundance ratio of the forming material measured on each of the extracted 100 μm x 100 μm surfaces is 21.7% or less.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
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| SG10202012900SA SG10202012900SA (en) | 2019-12-27 | 2020-12-22 | Polishing cloth |
| CN202011536463.1A CN113047056A (en) | 2019-12-27 | 2020-12-23 | Abrasive cloth |
| TW109146017A TWI922453B (en) | 2019-12-27 | 2020-12-24 | Polishing cloth |
| JP2025012020A JP2025061874A (en) | 2019-12-27 | 2025-01-28 | Polishing cloth |
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| JP2025012020A Division JP2025061874A (en) | 2019-12-27 | 2025-01-28 | Polishing cloth |
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| JP2017013149A (en) | 2015-06-29 | 2017-01-19 | 株式会社クラレ | Polishing pad |
| JP2019025549A (en) | 2017-07-25 | 2019-02-21 | ニッタ・ハース株式会社 | Polishing cloth |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2017013149A (en) | 2015-06-29 | 2017-01-19 | 株式会社クラレ | Polishing pad |
| JP2019025549A (en) | 2017-07-25 | 2019-02-21 | ニッタ・ハース株式会社 | Polishing cloth |
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| SG10202012900SA (en) | 2021-07-29 |
| JP2021107106A (en) | 2021-07-29 |
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